diff --git a/miner/worker.go b/miner/worker.go
index e5348cef425d..89064c3b9546 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -169,7 +169,7 @@ func (self *worker) pending() (*types.Block, *state.StateDB) {
 			self.current.txs,
 			nil,
 			self.current.receipts,
-		), self.current.state
+		), self.current.state.Copy()
 	}
 	return self.current.Block, self.current.state.Copy()
 }